Driver: force restricted IT blocks for Windows on ARM

Windows on ARM expects ARMv8 (restricted IT) conditional instructions only.
Force enable the restricted IT mode via the backend option when targeting WoA.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209086 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index b0425cbe08a7540a45d950a16fd9c4ccfaf0cb05..7862ffb446e2cbadf49b664abaea60191b95c76d 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -3451,6 +3451,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       CmdArgs.push_back("-backend-option");
       CmdArgs.push_back("-arm-no-restrict-it");
     }
+  } else if (TT.isOSWindows() && (TT.getArch() == llvm::Triple::arm ||
+                                  TT.getArch() == llvm::Triple::thumb)) {
+    // Windows on ARM expects restricted IT blocks
+    CmdArgs.push_back("-backend-option");
+    CmdArgs.push_back("-arm-restrict-it");
   }
 
   // Forward -f options with positive and negative forms; we translate

diff --git a/test/Driver/woa-restrict-it.c b/test/Driver/woa-restrict-it.c
new file mode 100644 (file)
index 0000000..c046991
--- /dev/null
+++ b/test/Driver/woa-restrict-it.c
@@ -0,0 +1,4 @@
+// RUN: %clang -target armv7-windows -### %s 2>&1 | FileCheck %s
+
+// CHECK: "-backend-option" "-arm-restrict-it"
+